JP6567951B2 - Gas exhaust method - Google Patents

Description

  The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a gas exhaust method for a plasma processing apparatus.

  As background art of this technical field, Japanese Patent Application Laid-Open No. 59-009171 (Patent Document 1), Japanese Patent Application Laid-Open No. 61-052374 (Patent Document 2), Japanese Patent Application Laid-Open No. 63-126682 (Patent Document 3) and There exists Unexamined-Japanese-Patent No. 63-317680 (patent document 4).

  Japanese Patent Application Laid-Open No. 59-009171 (Patent Document 1) describes a method for forming a heat insulating and abrasion resistant coating layer on an inner peripheral surface of a metal cylinder.

Japanese Laid-Open Patent Publication No. 61-052374 (Patent Document 2) discloses a metal mixture comprising a Cr oxide hardened on the surface of a metal substrate and at least one of Zn, Ni, Cr, Al ₂ O ₃ and SiO _2. A method for forming a coating layer firmly bonded to a powder is described.

  Japanese Patent Laid-Open No. 63-126682 (Patent Document 3) describes a positioning pin for projection welding coated with a chemically densified ceramic having a film thickness of 30 to 200 μm.

  In JP-A-63-317680 (Patent Document 4), ammonium chromate or ammonium dichromate is added to an aqueous chromic anhydride solution to be impregnated so as to be 10% or less by weight with respect to the chromic acid content. A method for forming a chromium oxide film is described.

JP 59-009171 A JP 61-052374 A JP 63-126682 A Japanese Unexamined Patent Publication No. Sho 63-317680

  In the gas supply pipe provided in the plasma processing apparatus, a hard film is formed on the surface of the base material in order to prevent a reaction between the base material (for example, stainless steel) of the gas supply pipe and the gas. However, there is a problem in that the substance constituting the hard film is vaporized and liberated and flows into the processing chamber disposed inside the vacuum vessel provided in the plasma processing apparatus, contaminating the processing chamber or adhering to the upper surface of the semiconductor wafer. It was happening.

  In order to solve the above problems, a gas exhaust method of a plasma processing apparatus according to the present invention is formed on the inner wall of a gas supply pipe by filling a gas supply pipe for supplying gas into the processing chamber with a halogen-based gas. A step of forming a reactive compound by a reaction between the chromium passivation film and the halogen-based gas, and a step of exhausting the reactive compound together with the halogen-based gas by an exhaust pump through an exhaust pipe communicating with the gas supply pipe. In the step of exhausting the reaction compound, the reaction compound and the halogen-based gas are exhausted at the first pressure at which the reaction compound vaporizes.

  According to the present invention, in the plasma processing apparatus, contamination in the processing chamber due to the gas supply pipe can be reduced. Thereby, the operation stop time of the plasma processing apparatus can be shortened.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is the schematic explaining the introduction mechanism and exhaust mechanism of the process gas of the microwave plasma etching apparatus by an Example. For describing the physical properties of the reaction the compounds according to the embodiment, it is a graph showing the relationship between vapor pressure and temperature chromyl chloride _{(Cr 2 O 2 Cl 2)} . It is a flowchart figure which shows the flow of operation of each valve | bulb in a cycle purge operation | work for demonstrating the gas exhaustion method of the microwave plasma etching apparatus by an Example. It is the schematic which shows the gas filling path | route in the cycle purge operation | work for demonstrating the gas exhaustion method of the microwave plasma etching apparatus by an Example. (A) is a schematic diagram which shows the surface state of the hard film formed in the inner wall of the gas piping before implementation of cycle purge. (B) is a schematic diagram which shows the surface state of the hard film formed in the inner wall of the gas piping after cycle purge implementation.

  In the following embodiments, when necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other, and one is the other. There are some or all of the modifications, details, supplementary explanations, and the like.

  Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps) are not necessarily indispensable unless otherwise specified and clearly considered essential in principle. Needless to say.

  In addition, when referring to “consisting of A”, “consisting of A”, “having A”, and “including A”, other elements are excluded unless specifically indicated that only that element is included. It goes without saying that it is not what you do. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  In all the drawings for explaining the following embodiments, components having the same function are denoted by the same reference numerals in principle, and repeated description thereof is omitted. Hereinafter, the present embodiment will be described in detail with reference to the drawings.

(Detailed description of the issue)
First, since it seems that the gas exhaust method of the plasma processing apparatus by embodiment of this invention will become clearer, the contamination resulting from the gas supply piping of the plasma processing apparatus examined by the present inventors until now is demonstrated.

  In the manufacture of semiconductor devices, plasma processing apparatuses using plasma are widely used. For example, in an etching apparatus, first, a semiconductor wafer is held on a table provided in a processing chamber disposed inside a vacuum vessel. Subsequently, an electric field or magnetic field is supplied into the processing chamber while supplying a processing gas, which is formed in advance on the upper surface of the semiconductor wafer in the processing chamber and is suitable for processing a thin film for forming a semiconductor circuit. As a result, the particles of the processing gas are excited to form plasma, and the thin film is processed along the mask pattern disposed thereon.

In the process of processing a thin film previously formed on the upper surface of the semiconductor wafer, a substance having a high reactivity with a processing gas for a silicon (Si) compound or an aluminum (Al) alloy that forms a semiconductor circuit. For example, a halogen-based gas is often used. In a gas supply pipe for supplying such a gas into the processing chamber, a material having excellent corrosion resistance is used for a member in contact with the gas. For example, in a gas supply pipe that supplies chlorine (Cl ₂ ) gas or a gas containing this compound as an element of composition, stainless steel (SUS316L) is generally used for its inner wall.

  However, the elements of iron (Fe), chromium (Cr) or nickel (Ni) constituting the stainless steel cause an interaction with the supplied gas. For this reason, the reaction compound rides on the flow of the processing gas and flows into the processing chamber and adheres to the upper surface of the semiconductor wafer, or remains as a gas around the upper surface of the semiconductor wafer. There has been a problem that a member to be processed or a surface of a transfer robot is contaminated.

Therefore, in order to solve such a problem, a conventional plasma processing apparatus uses a gas supply pipe in which a hard film is formed on the surface of a member in contact with the gas. For example, a chromium passivation film composed of fine particles of chromium (III) oxide (Cr ₂ O ₃ ) obtained by chemically changing chromium oxide, that is, chromium (VI) oxide (CrO ₃ ), is formed on the surface of stainless steel. Gas supply pipes are used. Such a technique is described in, for example, Patent Documents 1, 2, 3, and 4 described above.

  However, as a result of investigations by the present inventors, it has become clear that the following points are insufficiently considered in the gas supply pipe in which a hard film such as a chromium passivation film is formed on the surface of the member in contact with the gas. It was.

  That is, the hard coating did not have sufficient corrosion resistance and immobility for all of the operating conditions that change variously when the plasma processing apparatus is operated. In general, the processing conditions for a semiconductor wafer, such as temperature and pressure, can be changed according to the material and structure of a thin film to be processed formed on the upper surface of the semiconductor wafer. Therefore, in some processing conditions for the semiconductor wafer, there is a problem that the material constituting the hard film is vaporized and liberated, flows into the processing chamber, contaminates the processing chamber, or adheres to the upper surface of the semiconductor wafer. It was.

Further, according to the study by the present inventors, the hard coating formed on the inner wall of the gas supply pipe is mainly a new member, and its surface is rough. Therefore, boron trichloride (BCl ₃₎ is used as a processing gas. ) Or a halogen-based gas such as chlorine (Cl ₂ ), it became clear that the increase in the amount of contamination becomes significant. For this reason, it is necessary to reduce the amount of contamination by smoothing the hard film formed on the inner wall of the gas supply pipe. However, to smooth the hard coating formed on the inner wall of the gas supply pipe, and to clean the interior of the processing chamber and replace parts due to contamination inside the vacuum vessel, it is necessary to shut down the plasma processing equipment for a long time. This was a major cause of a decrease in the operating rate of the plasma processing apparatus.

  An object of the present invention is to reduce contamination in a processing chamber caused by gas supply piping in a plasma processing apparatus. This also shortens the operation stop time of the plasma processing apparatus.

  The gas exhaust method of the plasma processing apparatus according to this embodiment will be described below.

≪Process gas introduction mechanism and exhaust mechanism≫
FIG. 1 is a schematic diagram for explaining a process gas introduction mechanism and an exhaust mechanism of an electron cyclotron resonance (micron) plasma etching apparatus according to this embodiment.

  As shown in FIG. 1, a cylinder 101 that is a gas supply source is connected to a gas pipe 102 and includes a path for supplying gas into a processing chamber 106.

  On the path of the gas pipe 102, a valve 103 and a valve 105 for opening or blocking a flow path inside the gas pipe 102 are arranged. The valve 105 is a gas pipe according to the interruption of processing in the processing chamber 106. The channel 102 is opened and closed.

  Further, a gas line 104 that is a plurality of gas introduction paths is provided on the upstream side of the valve 105 on the path of the gas pipe 102. The gas line 104 includes 16 gas paths of the gas lines 104-1 to 16-16, and a gas of a substance having a different element or composition (a different type) flows therethrough. Different types of gases flowing through the gas lines 104-1 to 16-16 flow into the processing chamber 106 through the gas pipe 102 as a processing gas mixed in the junction.

  The processing gas introduced into the processing chamber 106 is exhausted by the operations of the vacuum pump 108 and the roughing pump 110. The amount and speed of the exhausted gas vary depending on the rotation speed of the vacuum pump 108 and the area of the opening corresponding to the angle of the rotary valve 107. The pressure value and the degree of vacuum in the processing chamber 106 are adjusted by the balance between the supply amount and speed of the processing gas and the exhaust amount and speed of the rotary valve 107.

  On each path of the gas lines 104-1 to 16, mass flow controllers 104-1 b to 16 b, which are regulators that variably increase or decrease the flow rate and speed of the gas flowing inside, are arranged. Valves 104-1a to 16a and valves 104-1c to 16c for opening or blocking each of -1 to 16 are arranged. Further, each of the gas lines 104-1 to 16-16 is connected to a cylinder 101 which is a gas supply source on the upstream side.

  A bypass line 112 is connected between the valve 105 and the gas line 104-1 to 16 on the path of the gas pipe 102 or a junction where the gas line 104 joins, and the bypass line 112 is a roughing pump. 110 is provided with a connecting portion between an inlet 110 and a bypass line 113 having one end connected thereto. Further, on the path of the bypass line 112, a valve 111 for opening or blocking the internal flow path is provided. Each of the gas lines 104-1 to 16-16 includes a purge line that is a gas purge path connected to the bypass line 113, and an internal flow path is opened on each path of the purge line. Alternatively, valves 104-1d to 16d for shutting off are provided.

  The roughing pump 110 is usually an exhaust pump connected to an exhaust port of a vacuum pump 108 such as a turbo molecular pump. The turbo molecular pump has low exhaust efficiency and cannot exhaust the gas pipe 102, the gas line 104, or the processing chamber 106 in a relatively high pressure range where the exhaust cannot be performed. Therefore, a valve for opening or blocking the internal flow path on the line of the line connecting the vacuum pump 108 and the inlet of the roughing pump 110 and closer to the vacuum pump 108 than the connecting portion to which the bypass line 113 is connected. 109 is arranged. By shutting off the flow path with this valve 109, the gas pipe 102, the gas line 104 or the inside of the processing chamber 106 from the bypass line 113 to the reduced pressure with a high degree of vacuum that can be used by the turbo molecular pump from the atmospheric pressure. (The roughing line in the processing chamber 106 is not shown). A valve 114 for opening or blocking the flow path inside the bypass line 113 is disposed on the path of the bypass line 113.

≪Identification of contaminants≫
In this embodiment, in order to identify the gas that causes the generation of contaminants, the gas is supplied into the processing chamber 106 in each of the gas lines 104-1 to 13-13 (104-14 to 16 gas types overlap). It was introduced, and a contamination degree confirmation test in the processing chamber 106 at the initial use of the gas line was conducted. Tests were performed using argon (Ar), nitrogen trifluoride (NF ₃ ), hydrogen bromide (HBr), oxygen (O ₂ ), silicon tetrachloride (SiCl ₄ ), chlorine (Cl ₂ ), sulfur hexafluoride (SF ₆ ), boron trichloride (BCl ₃ ), carbon tetrafluoride (CF ₄ ), nitrogen (N ₂ ), hydrogen (H ₂ ) and trifluoromethane (CHF ₃ ). As a result, contamination in the processing chamber 106 by silicon chloride (SiCl ₄ ), chlorine (Cl ₂ ), boron trichloride (BCl ₃ ), and hydrogen bromide (HBr), which are halogen-based gases, was confirmed.

  Table 1 shows the result of the contamination degree confirmation test (before the cycle purge) at the initial use of the gas line.

As a result of the contamination degree confirmation test, the processing chamber 106 with silicon chloride (SiCl ₄ ), chlorine (Cl ₂ ), boron trichloride (BCl ₃ ), and hydrogen bromide (HBr), which are halogen-based gases, at the initial use of the gas line. The contamination inside was confirmed. In particular, a high contamination level of 32.9 (E10 atom / cm ² ) was confirmed in boron trichloride (BCl ₃ ). From the above results, it was estimated that the four types of gases were the cause of contamination in the processing chamber 106. In addition, it is confirmed that the contamination level is lowered by continuing the introduction of the gas estimated to be the cause of contamination into the processing chamber 106 and the exhaust from the processing chamber 106.

By the way, boron trichloride (BCl ₃ ) used as a processing gas in this embodiment, and a hard film formed on the inner wall of the gas pipe 102 for supplying gas to the processing chamber 106, for example, chromium oxide (Cr ₂ O _3). ) Is estimated to cause the following chemical reaction.

3Cr ₂ O ₃ (solid) + 2BCl ₃ (gas) ⇒
3Cr ₂ O ₂ Cl ₂ (liquid) + B ₂ O ₃ (solid) Chemical reaction formula (1)
From this chemical reaction formula (1), when boron trichloride (BCl ₃ ) is supplied, chromyl chloride (Cr ₂ ), which is a chloride of chromium oxide (Cr ₂ O ₃ ), is formed on the inner wall of the gas pipe 102. It can be seen that a liquid of O ₃ Cl ₂ ) is formed.

FIG. 2 is a graph showing the relationship between the vapor pressure and temperature of chromyl chloride (Cr ₂ O ₂ Cl ₂ ), which is a chloride of chromium oxide (Cr ₂ O ₃ ), represented by chemical reaction formula (1). It is. The vertical axis represents the vapor pressure of chromyl chloride (Cr ₂ O ₂ Cl ₂ ), and the horizontal axis represents the system temperature.

As shown in FIG. 2, when the temperature of the gas pipe 102 is normal temperature (20 ° C.), when the pressure inside the gas pipe 102 becomes 1.9 kPa or less, chromyl chloride (Cr ₂ O ₂ Cl ₂ ) Vaporize. When vaporized chromyl chloride (Cr ₂ O ₂ Cl ₂ ) is introduced into the processing chamber 106 through the gas pipe 102, chromyl chloride (Cr ₂ O ₂ Cl ₂ ) liquefies and adheres in the processing chamber 106. Thereafter, the chromium (Cr) component interacts with the thin film formed on the upper surface of the semiconductor wafer in the processing chamber 106, and a compound is formed, which may contaminate the semiconductor wafer.

Further, when etching a plurality of different types of multilayer films deposited on the upper surface of the semiconductor wafer, it is necessary to etch each film layer under different conditions. Therefore, the semiconductor wafer is etched by providing a plurality of steps. At this time, between the steps, the inside of the processing chamber 106 and the inside of the gas pipe 102 are evacuated by the operation of the vacuum pump 108, and the processing gas and product used in the previous step are exhausted. At this time, the pressure inside the processing chamber 106 and the inside of the gas pipe 102 becomes 1.9 kPa or less, and the liquid of chromyl chloride (Cr ₂ O ₂ Cl ₂ ) is vaporized, which may contaminate the processing chamber 106.

  Therefore, in order to solve such a problem, it is necessary to prevent contamination caused by the gas pipe 102 from being introduced into the processing chamber 106.

≪Gas exhaust method and effect≫
Next, the gas exhaust method of the plasma processing apparatus according to the present embodiment will be described in detail. By this gas exhaust method, it is possible to suppress introduction of contaminants due to the gas pipe 102 into the processing chamber 106.

  FIG. 3 is a flowchart showing the flow of each valve operation in the cycle purge operation for explaining the gas exhaust method of the microwave plasma etching apparatus according to the present embodiment. FIG. 4 is a schematic view showing a gas filling path in a cycle purge operation for explaining a gas exhaust method of the microwave plasma etching apparatus according to the present embodiment.

  First, the cylinder 101, the gas valve 103, and the gas valve 104-1a which are gas supply sources are opened, and the mass flow controller 104-1b is set to the maximum flow rate (step 301). Here, the gas valves 104-1c and 104-1d are closed.

  Next, by closing the cylinder 101 and the gas valve 103, the inside of the path 401 (path indicated by a relatively thick line in FIG. 4) of the gas pipe 102 is filled with high-pressure gas (step 302).

Thereafter, the filling state is maintained for 10 minutes or more (step 303). Accordingly, the reaction between the hard film (for example, chromium oxide (Cr ₂ O ₃ )) formed on the inner wall of the path 401 of the gas pipe 102 and the gas is promoted.

Next, the gas valve 109 is closed, the gas valve 104-1 d and the gas valve 114 are opened, and exhausted by the roughing pump 110, whereby the reaction compound (for example, chromyl chloride (Cr ₂ O ₂ chloride) adhering to the inner wall of the path 401 of the gas pipe 102. Cl ₂ )) is exhausted together with the gas filled in the path 401 of the gas pipe 102 (step 304).

The temperature of the gas pipe 102 during exhaust is, for example, normal temperature (20 ° C.), and the pressure inside the gas pipe 102 is, for example, 1.9 kPa or less. The pressure inside the gas pipe 102 at the time of exhaust is set to 1.9 kPa or less at which the reaction compound (for example, chromyl chloride (Cr ₂ O ₂ Cl ₂ )) is vaporized and liberated, but the effect can be expected if the pressure is lower. . Further, the exhaust time was set to 1 minute or longer, which is estimated that the reaction compound was almost removed.

  Next, the gas valve 114 and the gas valve 104-1d are closed, the mass flow controller 104-1b is set to the minimum flow rate, and the gas valve 104-1a is closed (step 305).

  Next, in order to supply gas again, the cylinder 101 and the gas valve 103 are opened (step 306).

  The above flowchart is defined as one cycle, and after 10 cycles (step 307), a contamination degree confirmation test in the processing chamber 106 was performed.

  Table 1 shows the results of the contamination degree confirmation test after the cycle purge.

After the cycle purge, the contamination levels of halogen-based gases such as silicon chloride (SiCl ₄ ), chlorine (Cl ₂ ), boron trichloride (BCl ₃ ), and hydrogen bromide (HBr) are 1.0 (E10 atoms / cm ² ), and the pollution level was lowered as compared with the pollution level before the cycle purge was performed (when the gas line was initially used).

FIG. 5 is a schematic diagram of a hard coating formed on the inner wall of a gas pipe provided in the plasma processing apparatus according to this embodiment. For the hard film, chromium oxide (Cr ₂ O ₃ ), which is a chromium passive film, is used.

  FIG. 5 (a) shows the surface state of the hard coating formed on the inner wall of the gas pipe before the cycle purge. Many rough inner wall surfaces 501 are seen, and as shown in Table 1, The pollution level was also high. On the other hand, FIG. 5 (b) shows the surface state of the hard coating formed on the inner wall of the gas pipe after the cycle purge, and many smooth inner wall surfaces 502 are seen, as shown in Table 1. As a result, the degree of contamination in the processing chamber was also low.

≪Modification≫
The pressure inside the gas pipe 102 when boron trichloride (BCl ₃ ) used as a processing gas in the cycle purge work is filled into the path 401 of the gas pipe 102 by the cycle purge work shown in FIG. The gas supply pressure of the cylinder 101 is 40 kPa or less. In the case of such a pressure, according to FIG. 2, if the temperature of the gas pipe 102 is 87 ° C., chromyl chloride (Cr ₂ O ₂ Cl ₂ ) is vaporized.

  From the above, by installing a temperature-controllable heater in the gas filling path (for example, the path 401 shown in FIG. 4) of the gas pipe 102 in the cycle purge operation shown in FIG. 3, vaporization and liberation at the time of gas filling are performed. This can be promoted, and smoothing of the inner wall of the gas pipe 102 can be accelerated. In addition, it is estimated that the temperature control range of the heater is 20 ° C. or more and 90 ° C. or less which is normal temperature.

  As described above, according to the present embodiment, the reaction compound generated from the hard coating formed on the inner wall of the gas pipe 102 can be exhausted without being introduced into the processing chamber 106. Contamination can be reduced, and adhesion of contaminants to the upper surface of the semiconductor wafer can be prevented. In addition, since the hard coating formed on the inner wall of the gas pipe 102 can be easily smoothed and contamination in the processing chamber 106 can be reduced, the frequency of cleaning and replacement of parts in the processing chamber 106 can be reduced. Can be reduced. Thereby, since the operation stop time of the plasma processing apparatus can be shortened, the operating rate of the plasma processing apparatus can be increased.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the present embodiment, chromium oxide (Cr ₂ O ₃ ), which is a chromium passive film, is exemplified as the hard film formed on the surface of the base material of the gas supply pipe. However, the present invention is not limited to this. Absent.

  In this embodiment, a gas exhaust method applied to a plasma processing apparatus, particularly, a plasma etching apparatus has been described. However, the present invention is not limited to this, and is applicable to, for example, a plasma CVD (Chemical Vapor Deposition) apparatus. can do.

101 Cylinder 102 Gas Pipe 103 Valve 104 Gas Line 104-1 to 16 Gas Line 104-1a to 16a Valve 104-1b to 16b Mass Flow Controller 104-1c to 16c Valve 104-1d to 16d Valve 105 Valve 106 Processing Chamber 107 Rotation Valve 108 Vacuum pump 109 Valve 110 Roughing pump 111 Valve 112 Bypass line 113 Bypass line 114 Valve 401 Path 501 Inner wall surface 502 of gas piping Inner wall surface of gas piping

Claims (10)

A gas used in a semiconductor manufacturing apparatus, comprising: a processing chamber; a supply pipe that supplies gas into the processing chamber; an exhaust pipe that communicates with the supply pipe; and an exhaust pump that exhausts the processing chamber and the supply pipe. In the gas exhaust method to exhaust,
Filling the supply pipe with a gas that forms a reaction compound by reaction with a hard coating formed inside the supply pipe;
Exhausting the gas filled in the supply pipe and the reaction compound with the exhaust pump at a predetermined pressure through the exhaust pipe without passing through the processing chamber ;
The gas exhaust method according to claim 1, wherein the predetermined pressure is a pressure at which the reaction compound vaporizes. A gas exhaust method for exhausting a gas used in a semiconductor manufacturing apparatus, comprising: a processing chamber; a supply pipe for supplying gas into the processing chamber; an exhaust pipe communicating with the supply pipe; and an exhaust pump for exhausting the processing chamber In
Filling the supply pipe with a gas that forms a reaction compound by reaction with a hard coating formed inside the supply pipe;
Evacuating the gas filled in the supply pipe and the reaction compound with the exhaust pump through the exhaust pipe at a predetermined pressure,
The predetermined pressure is a pressure at which the reaction compound vaporizes,
A gas exhausting method, wherein the gas filled in the supply pipe is silicon chloride gas, boron trichloride gas or hydrogen bromide gas . A gas exhaust method for exhausting a gas used in a semiconductor manufacturing apparatus, comprising: a processing chamber; a supply pipe for supplying gas into the processing chamber; an exhaust pipe communicating with the supply pipe; and an exhaust pump for exhausting the processing chamber In
Filling the supply pipe with a gas that forms a reaction compound by reaction with a hard coating formed inside the supply pipe;
Evacuating the gas filled in the supply pipe and the reaction compound with the exhaust pump through the exhaust pipe at a predetermined pressure,
The predetermined pressure is a pressure at which the reaction compound vaporizes,
A gas exhausting method, wherein the gas filled in the supply pipe is silicon chloride gas or boron trichloride gas . The gas exhaust method according to claim 1 ,
A gas exhausting method, wherein the gas filled in the supply pipe is a halogen-based gas . The gas exhaust method according to claim 4 ,
The gas exhaust method according to claim 1, wherein the halogen-based gas is silicon chloride gas, chlorine gas, boron trichloride gas, or hydrogen bromide gas . The gas exhaust method according to any one of claims 1 to 3 ,
The gas exhaust method according to claim 1, wherein the hard coating is chromium oxide . The gas exhaust method according to claim 6 ,
The reaction compound is chromyl chloride,
The gas exhaust method according to claim 1, wherein the predetermined pressure is a pressure of 1.9 kPa or less . The gas exhaust method according to claim 1 ,
The gas exhaust method according to claim 1, wherein the temperature of the supply pipe is 20 ° C or higher and 90 ° C or lower . The gas exhaust method according to claim 1,
The gas exhaust method according to claim 1, wherein a time for filling the supply pipe with a gas that forms a reaction compound by a reaction with a hard coating formed inside the supply pipe is 10 minutes or more. The gas exhaust method according to claim 1,
The gas exhausting method, wherein the filling step and the exhausting step are alternately repeated 10 times or more.

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